1928 Harley JDH Two Cam Classic Motorcycle Project

I have long been fascinated with early Harley twins, especially the J series models from the 1920s. The most exciting of these street bikes was the limited production JDH “Two Cam” hot rod Harleys produced and sold in 1928 and 1929 only.

Rare Harley JDH Two Cam engine

The lower end of the JDH engine (above) looks different from the more popular J and JD as the cam chest curves up in the back and the lifter blocks are mounted above the cases. Th J and JD (below) lower ends had an oval-shaped cam cover and the pushrod tubes screwed directly into the cases.

More popular Harley J or JD engine design

In 2011 I worked with Dale Walksler and the crew at Wheels Through Time museum to rebuild my 1929 Harley JDH. We rebuilt it from top to bottom with the intention of riding it over 3,000 miles in two weeks from New York to San Francisco on the 2012 Motorcycle Cannonball Endurance Run. The bike ran great and I became a huge fan of the fabled Two Cam hot rod Harleys.

While these JDH motors are quite rare (I have heard Harley might have produced less than 1,800 of them in total) I am fortunate enough to have been offered another one for sale. It was just before the Cannonball so I did the deal and parked the bike (a modified 1928 JDH) in storage until I could get the time to give it the attention it deserves.

Modified 1928 Harley JDH Two Cam motorcycle as purchased

This is pretty much how the bike looked when I purchased it. Most of it appears to be real and original 1928 Harley parts.

Left side of the lightly modified 1928 Harley JDH motorcycle

Someone chromed the front fork legs. The one-piece, unhinged rear fender is not correct, and nor is the Bosch ZEV magneto ignition, exhaust or later VL transmission. We did get it to fire and run briefly, but with motorcycles as old and rare as this, I’d like to disassemble, inspect and rebuild the engine before riding it far.

My plan is to carefully strip down and rebuild this bike as a street racer. Because this is a magneto (no battery or way to charge a battery) powered bike I will probably remove the horn, and possibly the toolbox too – less weight and less visual clutter. Yes, most bikes of this era (Harley introduced the front brake in 1928) had the brake lever on the left side. It should go without saying I will not do any damage to original parts and keep them safe and out of the way on this build.

Rear wheels with race-style drilled out brake arm

You can see a previous owner has already drilled out the brake plate to reduce weight and give it that racer look. I wonder why he left the speedometer drive ring gear on the wheel that adds a little weight? Unless I run a speedometer (not likely) I will remove the speedo drive gear.

Hollywood bars with cross-over brace added. The dash has keys for the ignition and the lights.

Here is a good view from the rider’s perspective. Low and wide bars with the brace welded in place. Throttle on the right and ignition advance/retard on the left grip with internal cabling. The dash mounts the ignition key on the left and lights on the right. Three speed hand shifter on the left (with the green die shift knob). The cap on the right is for gas, the front cap on the left is for the oil tank, and the rear one is for gas. The knob below that is the hand pump for oil.

Not original, but pretty cool STOP brake light.

This is pretty much how the bike has looked for the last 5 or so years. And this is how it looks now. As I get time I’d like to start redoing this bike as a period street racer. Who knows, perhaps we might even try it on a Land Speed Race one-mile track. Lots to do before I even consider that, but it sure is a nice goal.